The Biostatistics Core will provide statistical and data entry support for CFAR investigators. In particular, the biostatistical core will provide a crucial link between the large number of biostatical faculty at the University of Washington and the Fred Hutchinson Cancer Research Institute who are developing new statistical methods for AIDS research and the clinical and laboratory researchers using the CFAR. This link will benefit both groups. The Biostatistical Core will provide advanced statistical methods and expertise, which have been developed under Dr. Fleming's AIDS Methodology grant, to CFAR investigators; the clinical and laboratory researcher utilizing the Biostatistical Core will provide datasets for analysis which may motivate the development of new statistical methods under the Methodology grant. To promote and facilitate these multidisciplinary interactions the Biostatistics Core will 1) provide statistical collaboration and consultation on study design; forms design, evaluation and pretesting; and data analysis; 2) provide data entry services according to a charge-back system; 3) collaborate in the writing of manuscripts, paying special attention to accurate descriptions of study design, data analysis and interpretation of results; 4) serve on Data and Safety Monitoring Boards for CFAR investigators, as needed; 5) develop, adapt and/or implement new or novel statistical methods as needed; and 6) maintain computing facilities (3 DECstations 3100's) which are available (both on site and by remote login) to any CFAR investigator. The Biostatical Core will form a particularly valuable resource for new investigators developing proposals for peer-reviewed competition for funding and for established investigators in need of advanced biostatistical expertise to pursue innovative or unanticipated research directions.